| 1. |
- Zamora, Juan Carlos, et al.
(författare)
-
Considerations and consequences of allowing DNA sequence data as types of fungal taxa
- 2018
-
Ingår i: IMA Fungus. - : INT MYCOLOGICAL ASSOC. - 2210-6340 .- 2210-6359. ; 9:1, s. 167-185
-
Tidskriftsartikel (refereegranskat)abstract
- Nomenclatural type definitions are one of the most important concepts in biological nomenclature. Being physical objects that can be re-studied by other researchers, types permanently link taxonomy (an artificial agreement to classify biological diversity) with nomenclature (an artificial agreement to name biological diversity). Two proposals to amend the International Code of Nomenclature for algae, fungi, and plants (ICN), allowing DNA sequences alone (of any region and extent) to serve as types of taxon names for voucherless fungi (mainly putative taxa from environmental DNA sequences), have been submitted to be voted on at the 11th International Mycological Congress (Puerto Rico, July 2018). We consider various genetic processes affecting the distribution of alleles among taxa and find that alleles may not consistently and uniquely represent the species within which they are contained. Should the proposals be accepted, the meaning of nomenclatural types would change in a fundamental way from physical objects as sources of data to the data themselves. Such changes are conducive to irreproducible science, the potential typification on artefactual data, and massive creation of names with low information content, ultimately causing nomenclatural instability and unnecessary work for future researchers that would stall future explorations of fungal diversity. We conclude that the acceptance of DNA sequences alone as types of names of taxa, under the terms used in the current proposals, is unnecessary and would not solve the problem of naming putative taxa known only from DNA sequences in a scientifically defensible way. As an alternative, we highlight the use of formulas for naming putative taxa (candidate taxa) that do not require any modification of the ICN.
|
|
| 2. |
- Abarenkov, Kessy, et al.
(författare)
-
PlutoF—a web based workbench for ecological and taxonomic research, with an online implementation for fungal ITS sequences
- 2010
-
Ingår i: Evolutionary Bioinformatics. - 1176-9343. ; 6, s. 189-196
-
Tidskriftsartikel (refereegranskat)abstract
- DNA sequences accumulating in the International Nucleotide Sequence Databases (INSD) form a rich source of information for taxonomic and ecological meta-analyses. However, these databases include many erroneous entries, and the data itself is poorly annotated with metadata, making it difficult to target and extract entries of interest with any degree of precision. Here we describe the web-based workbench PlutoF, which is designed to bridge the gap between the needs of contemporary research in biology and the existing software resources and databases. Built on a relational database, PlutoF allows remote-access rapid submission, retrieval, and analysis of study, specimen, and sequence data in INSD as well as for private datasets though web-based thin clients. In contrast to INSD, PlutoF supports internationally standardized terminology to allow very specific annotation and linking of interacting specimens and species. The sequence analysis module is optimized for identification and analysis of environmental ITS sequences of fungi, but it can be modified to operate on any genetic marker and group of organisms. The workbench is available at http://plutof.ut.ee.
|
|
| 3. |
- Abarenkov, Kessy, et al.
(författare)
-
The UNITE database for molecular identification and taxonomic communication of fungi and other eukaryotes: sequences, taxa and classifications reconsidered
- 2024
-
Ingår i: Nucleic Acids Research. - 0305-1048 .- 1362-4962. ; 52:D1, s. D791-D797
-
Tidskriftsartikel (refereegranskat)abstract
- UNITE (https://unite.ut.ee) is a web-based database and sequence management environment for molecular identification of eukaryotes. It targets the nuclear ribosomal internal transcribed spacer (ITS) region and offers nearly 10 million such sequences for reference. These are clustered into similar to 2.4M species hypotheses (SHs), each assigned a unique digital object identifier (DOI) to promote unambiguous referencing across studies. UNITE users have contributed over 600 000 third-party sequence annotations, which are shared with a range of databases and other community resources. Recent improvements facilitate the detection of cross-kingdom biological associations and the integration of undescribed groups of organisms into everyday biological pursuits. Serving as a digital twin for eukaryotic biodiversity and communities worldwide, the latest release of UNITE offers improved avenues for biodiversity discovery, precise taxonomic communication and integration of biological knowledge across platforms. Graphical Abstract
|
|
| 4. |
- Gohar, Daniyal, et al.
(författare)
-
Global diversity and distribution of mushroom-inhabiting bacteria
- 2022
-
Ingår i: Environmental Microbiology Reports. - : John Wiley & Sons. - 1758-2229 .- 1758-2229. ; 14:2, s. 254-264
-
Tidskriftsartikel (refereegranskat)abstract
- Mushroom-forming fungi are important sources of food and medicine in many regions of the world, and their development and health are known to depend on various microbes. Recent studies have examined the structure of mushroom-inhabiting bacterial (MIB) communities and their association with local environmental variables, but global-scale diversity and determinants of these communities remain poorly understood. Here we examined the MIB global diversity and community composition in relation to climate, soil and host factors. We found a core global mushroom microbiome, accounting for 30% of sequence reads, while comprising a few bacterial genera such as Halomonas, Serratia, Bacillus, Cutibacterium, Bradyrhizobium and Burkholderia. Our analysis further revealed an important role of host phylogeny in shaping the communities of MIB, whereas the effects of climate and soil factors remained negligible. The results suggest that the communities of MIB and free-living bacteria are structured by contrasting community assembly processes and that fungal-bacterial interactions are an important determinant of MIB community structure.
|
|
| 5. |
- Kõljalg, Urmas, et al.
(författare)
-
Towards a unified paradigm for sequence-based identification of fungi.
- 2013
-
Ingår i: Molecular ecology. - : Wiley. - 1365-294X .- 0962-1083. ; 22:21, s. 5271-7
-
Tidskriftsartikel (refereegranskat)abstract
- The nuclear ribosomal internal transcribed spacer (ITS) region is the formal fungal barcode and in most cases the marker of choice for the exploration of fungal diversity in environmental samples. Two problems are particularly acute in the pursuit of satisfactory taxonomic assignment of newly generated ITS sequences: (i) the lack of an inclusive, reliable public reference data set and (ii) the lack of means to refer to fungal species, for which no Latin name is available in a standardized stable way. Here, we report on progress in these regards through further development of the UNITE database (http://unite.ut.ee) for molecular identification of fungi. All fungal species represented by at least two ITS sequences in the international nucleotide sequence databases are now given a unique, stable name of the accession number type (e.g. Hymenoscyphus pseudoalbidus|GU586904|SH133781.05FU), and their taxonomic and ecological annotations were corrected as far as possible through a distributed, third-party annotation effort. We introduce the term 'species hypothesis' (SH) for the taxa discovered in clustering on different similarity thresholds (97-99%). An automatically or manually designated sequence is chosen to represent each such SH. These reference sequences are released (http://unite.ut.ee/repository.php) for use by the scientific community in, for example, local sequence similarity searches and in the QIIME pipeline. The system and the data will be updated automatically as the number of public fungal ITS sequences grows. We invite everybody in the position to improve the annotation or metadata associated with their particular fungal lineages of expertise to do so through the new Web-based sequence management system in UNITE.
|
|
| 6. |
- Nilsson, R. Henrik, 1976, et al.
(författare)
-
The UNITE database for molecular identification of fungi: handling dark taxa and parallel taxonomic classifications.
- 2019
-
Ingår i: Nucleic acids research. - : Oxford University Press (OUP). - 1362-4962 .- 0305-1048. ; 47:D1, s. D259-D264
-
Tidskriftsartikel (refereegranskat)abstract
- UNITE (https://unite.ut.ee/) is a web-based database and sequence management environment for the molecular identification of fungi. It targets the formal fungal barcode-the nuclear ribosomal internal transcribed spacer (ITS) region-and offers all ∼1 000 000 public fungal ITS sequences for reference. These are clustered into ∼459 000 species hypotheses and assigned digital object identifiers (DOIs) to promote unambiguous reference across studies. In-house and web-based third-party sequence curation and annotation have resulted in more than 275 000 improvements to the data over the past 15 years. UNITE serves as a data provider for a range of metabarcoding software pipelines and regularly exchanges data with all major fungal sequence databases and other community resources. Recent improvements include redesigned handling of unclassifiable species hypotheses, integration with the taxonomic backbone of the Global Biodiversity Information Facility, and support for an unlimited number of parallel taxonomic classification systems.
|
|
| 7. |
- Parmasto, Erast, et al.
(författare)
-
Phylogenetic taxonomy of Hymenochaete and related genera (Hymenochaetales)
- 2014
-
Ingår i: Mycological progress. - : Springer Science and Business Media LLC. - 1617-416X .- 1861-8952. ; 13:1, s. 55-64
-
Tidskriftsartikel (refereegranskat)abstract
- Species delimitation in Hymenochaete sensu lato was evaluated based on partial nucLSU rDNA sequences, isoenzyme analyses and morphological data. Analyses of LSU data revealed Hymenochaete sensu stricto and Pseudochaete as distinct monophyletic genera. Transfer of Hydnochaete olivacea into genus Pseudochaete and Dichochaete setosa into genus Hymenochaete (as H. resupinata) was supported by the results of molecular analyses. A new species Hymenochaete koeljalgii from Tanzania was described. The species of genus Hymenochaete sensu stricto were divided into four well-supported clades possessing no distinctive morphological characters.
|
|
| 8. |
- Svantesson, Sten, et al.
(författare)
-
Polyozellus vs. Pseudotomentella: generic delimitation with a multi-gene dataset
- 2021
-
Ingår i: Fungal Systematics and Evolution. - : Westerdijk Fungal Biodiversity Institute. - 2589-3823. ; 8
-
Tidskriftsartikel (refereegranskat)abstract
- Polyozellus and Pseudotomentella are two genera of closely related, ectomycorrhizal fungi in the order Thelephorales; the former stipitate and the latter corticioid. Both are widespread in the Northern Hemisphere and many species from both genera seem to be restricted to old growth forest. This study aimed to: a) identify genetic regions useful in inferring the phylogenetic relationship between Polyozellus and Pseudotomentella, b) infer this relationship with the regions identified and c) make any taxonomic changes warranted by the result. RPB2, mtSSU and nearly full-length portions of nrLSU and nrSSU were found to be comparatively easy to sequence and provide a strong phylogenetic signal. A STACEY species tree of these three regions revealed that Polyozellus makes Pseudotomentella paraphyletic. As a result, nearly all species currently placed in Pseudotomentella were recombined to Polyozellus. Pseudotomentella larsenii was found to be closer to Tomentellopsis than Polyozellus, but its placement needs further study and it was hence not recombined.
|
|
| 9. |
- Tedersoo, L., et al.
(författare)
-
454 Pyrosequencing and Sanger sequencing of tropical mycorrhizal fungi provide similar results but reveal substantial methodological biases
- 2010
-
Ingår i: New Phytologist. - : Wiley. - 0028-646X. ; 188:1
-
Tidskriftsartikel (refereegranskat)abstract
- Compared with Sanger sequencing-based methods, pyrosequencing provides orders of magnitude more data on the diversity of organisms in their natural habitat, but its technological biases and relative accuracy remain poorly understood. This study compares the performance of pyrosequencing and traditional sequencing for species’ recovery of ectomycorrhizal fungi on root tips in a Cameroonian rain forest and addresses biases related to multi-template PCR and pyrosequencing analyses. Pyrosequencing and the traditional method yielded qualitatively similar results, but there were slight, but significant, differences that affected the taxonomic view of the fungal community. We found that most pyrosequencing singletons were artifactual and contained a strongly elevated proportion of insertions compared with natural intra- and interspecific variation. The alternative primers, DNA extraction methods and PCR replicates strongly influenced the richness and community composition as recovered by pyrosequencing. Pyrosequencing offers a powerful alternative for the identification of ectomycorrhizal fungi in pooled root samples, but requires careful selection of molecular tools. A well-populated backbone database facilitates the detection of biological and technical artifacts. The pyrosequencing pipeline is available at http://unite.ut.ee/454pipeline.tgz.
|
|
